(also known as '''Digital Theater Systems'''), owned by '''DTS, Inc.''' (), is a multi-channel digital
Surround Sound format used for both commercial/theatrical and consumer grade applications. It is used for in-movie sound both on film and on DVD, and during the last few years of the format's existence, several
Laserdisc releases had DTS soundtracks.
One of the company's initial investors was
Film Director Steven Spielberg , who felt that theatrical sound formats up until the company's founding were no longer state of the art, and as a result were no longer optimal for use on projects where quality sound reproduction was of the utmost importance. Work on the format started in 1991, four years after
Dolby Labs started work on its new
Codec ,
Dolby Digital . The basic and most common version of the format is a 5.1 channel system, similar to a Dolby Digital setup, which encodes the audio as five primary (full-range) channels plus a special LFE (
Low-frequency Effect ) channel, for the
Subwoofer .
Note however that encoders and decoders support numerous channel combinations and stereo, four-channel and four-channel+LFE soundtracks have been released commercially on DVD, CD and Laserdisc.
Other newer DTS variants are also currently available, including versions that support up to seven primary audio channels plus one LFE channel (DTS-ES). DTS's main competitors in multichannel theatrical audio are
Dolby Digital and
SDDS , although only Dolby Digital and DTS are used on
DVD s and implemented in home theater hardware. Spielberg debuted the format with his 1993 production of ''
Jurassic Park '', which came slightly less than a full year after the official theatrical debut of Dolby Digital (''
Batman Returns ''). In addition, ''Jurassic Park'' also became the first home video release to contain DTS sound when it was released on LaserDisc in January 1997, two years after the first Dolby Digital home video release (''
Clear And Present Danger '' on Laserdisc) which debuted in January of 1995.
In theatrical use, information in the form of a modified
Time Code is optically imaged onto the film. An optical LED reader reads the timecode data off the film and sends it to the DTS processor which uses this timecode to synchronize the projected image with the soundtrack audio. The actual audio is recorded in compressed form on standard
CD-ROM media at a bitrate of 1,103 kbit/s. The processor also acts as a transport mechanism, as it holds and reads the audio discs. Newer units can generally hold three discs, allowing a single processor/transport to handle two-disc film soundtracks along with a third disc containing sound for theatrical trailers. In addition, specific elements of the imprinted timecode allow identifying data to be embedded within the code, ensuring that a certain film's
Soundtrack will only run with that film. DTS provided the Digital Audio for
IMAX until 2001, when
Dolby took over.
DTS and Dolby Digital (AC-3), DTS's chief competitor in the cinema and home theater market, are often compared due to their similarity in product goals. In theatrical installations, AC-3 audio is placed between sprocket holes, leaving the audio content susceptible to physical damage due to film wear and mishandling. DTS audio is stored on a separate set of CD-ROM media, whose greater storage capacity affords the potential to deliver better audio fidelity. However, the separation of print film and audiotrack is both a blessing and a curse. AC-3 (and SDDS) reside entirely on the 35 mm film itself, simplifying distribution by eliminating an extra (optional) deliverable. But DTS's CD-ROM media is not subject to the usual wear and damage suffered by the film print during the normal course of the movie's theatrical screening. Disregarding the separate CD-ROM assembly as a potential point of failure, the DTS audiopath comparatively impervious to film degradation, excepting that the film-printed timecode is completely destroyed.
In the consumer (home theater) market, AC-3 and DTS are close in terms of audio performance. When the DTS audio track is encoded at its highest legal bitrate (1,500 kbit/s), technical experts rank DTS as perceptually transparent for most audio program material (i.e., indistinguishable to the uncoded source in a
Double Blind test.) Dolby claims its competing AC-3 codec achieves similar transparency at its highest coded bitrate (640 kbit/s). However, in program material available to home consumers (DVD, broadcast and subscription Digital TV), neither AC-3 nor DTS run at its highest allowed bitrate. DVD and broadcast (ATSC) HDTV cap AC-3 bitrate at 448 kbit/s. But even at 448 kbit/s, consumer audio gear already enjoy better audio performance than theatrical (35 mm movie) installations, which are limited to even lower bitrates. When DTS-audio was introduced to the DVD specification, studios authored DVD-movies at DTS's full bitrate (1,536 kbit/s). Later movie titles were almost always encoded at a reduced bitrate of 768 kbit/s, ostensibly to increase the number of audio-tracks on the movie disc. At this reduced rate (768 kbit/s), DTS no longer retains audio transparency.
AC-3 and DTS are sometimes judged by their encoded bitrates. DTS proponents claim that the extra bits give higher fidelity and more dynamic range, providing a richer and more lifelike sound. But no conclusion can be drawn from their respective bitrates, as each codec relies on different coding tools and syntax to compress audio. When the DTS and AC-3 audiotracks on the same DVD are compared, some movies exhibit noticeable differences. A DTS track is often louder with less hiss, even at the same relative playback volume.
DTS is an enhanced copy ''
Les dinosaures muselés par deux français '', ''L'Expansion'' (October 21, 1993) of a
French patent called ''
LC Concept '', first used in 1990 for the movie ''
Cyrano De Bergerac '' which received the best sound award at the
César Awards in 1991.
César Awards, France: 1991 IMDB
On the consumer level, DTS is the oft-used shorthand for the
DTS Coherent Acoustics codec, transportable through
S/PDIF and used on
DVD s,
CDDA s,
LD s and in wave files. This system is the consumer version of the DTS standard, using a similar
Codec without needing separate DTS CD-ROM media.
There are significant technical differences between commercial/theatrical and home variants: the former being a traditional
ADPCM compression system and the latter a sophisticated hybrid perceptual and signal-redundancy compressor based on ADPCM called APTX-100.
Both music and movie DVDs allow delivery of DTS audio tracks. But DTS was not part of the original DVD specification (1997), so early DVD players did not recognize DTS audio tracks at all. The DVD specification was revised to allow optional inclusion of DTS audio tracks. The DVD title must carry one or more primary audio tracks in AC-3 or LPCM format (in Europe, MPEG-1 is also an allowed primary track format). The DTS audio track, if present, can be selected by the user. Modern DVD players generally rely on an external home theater receiver to decode DTS audio. DVD players with integrated DTS 5.1 decoders exist, but are not particularly common. Nearly all standalone receivers and many integrated ("home theater in a box") DVD player/receivers manufactured today can decode DTS.
For PC playback, many software players support the decoding of DTS. The
VideoLAN project has created a decoding module for DTS called
Libdca (formerly libdts), which is the first open source implementation of DTS.
Videolan features page
The Sony
Playstation 3 and
Xbox 360 are capable of DTS decoding and output via
Toslink or
HDMI (Xbox 360 Elite and newer models only) as LPCM. Neither console has the ability to decode DTS-HD High Resolution or Master Audio at this time. The PlayStation 3 can decode the "core" of DTS-HD internally at a bitrate of 1.5 Mbit/s while the Xbox 360 can output the bitstream itself via Toslink.
In addition to the standard 5.1 channel DTS Surround codec, the company has several other technologies in its product range designed to compete with similar systems from
Dolby Labs . The primary new technologies are:
- (DTS Extended Surround): includes two variants, ''DTS-ES Matrix'' and ''DTS-ES Discrete 6.1'', depending on how the sound was originally mastered and stored. DTS Extended Surround at timefordvd.com DTS-ES Discrete provides 6.1 discrete channels, with a discretely recorded (non- Matrixed ) center-surround channel; in home theater systems with a 7.1 configuration, the two rear-center speakers play in Mono . DTS-ES Matrix provides 5.1 discrete channels with a matrixed center-surround audio channel. DTS-ES commonly works on a matrix system, whereby processors that are compatible with the ES codec look for and recognize "flags" built into the audio coding and "un-fold" the rear-center sound from data that would otherwise be sent to rear surround speakers. This is notated as DTS-ES 5.1. Less frequently, DTS-ES data can be encoded with a discrete sixth audio channel (the rear-center), meaning that the audio data for the sixth channel is stored separately from the other information, and is not embedded or matrixed among other channels. This is notated as DTS-ES 6.1, as the center rear is completely discrete from the other channels. ES capable processors can recognize the discrete sixth channel, and play it back if connected to the necessary speaker(s). In contrast, Dolby's competing EX codec, which also boasts a center rear channel, can only handle matrixed data and does not support a discrete sixth channel. DTS-ES is backward compatible with standard DTS setups, so non-ES equipment which does not recognize the flags or with ES enabled equipment that lack the extra speaker connections, sound plays back in 5.1 as if it were standard DTS. Only a few DVD titles have been released with DTS-ES Discrete.
- : Neo:6, like Dolby's Pro Logic IIx system, can take stereo content and convert the sound into 5.1 or 6.1 channel format.
- : Allows the delivery of 5.1 channels of 24-bit, 96 kHz audio and high quality video on the DVD-Video format. Prior to the invention of DTS 96/24, it was only possible to deliver two channels of 24-bit, 96 kHz audio on DVD-Video. DTS 96/24 can also be placed in the video zone on DVD-Audio discs, making these discs playable on all existing DVD players.
- : Previously known as ''DTS++'' and ''DTS-HD'', DTS-HD Master Audio supports a virtually unlimited number of surround sound channels, can Downmix to 5.1 and two-channel, and can deliver audio quality at bit rates extending from DTS Digital Surround up to lossless (24-bit, 96 kHz). DTS-HD Master Audio is selected as an optional surround sound format for Blu-ray and HD DVD . However, currently there are no Blu-ray or HD DVD players that are able to decode DTS-HD Master Audio, but all Blu-ray and HD DVD players can decode the DTS "core" soundtrack at 1.5 Mbit/s. DTS-HD Master Audio and Dolby TrueHD are the only technologies that deliver compressed lossless surround sound for these new disc formats, ensuring the highest quality audio performance available in the new standards. (N.B.: DTS Coherent Acoustics coding system has been selected as mandatory audio technology for both the Blu-ray Disc (BD) and High Definition Digital Versatile Disc (HD DVD). ''DTS technology mandatory for next generation discs'' – dtsonline.com )
- : Like DTS-HD Master Audio, DTS-HD High Resolution audio is an extension to the original DTS audio format. It delivers up to 7.1 channels of sound at 96 kHz sampling frequency and 24 bit depth resolution. DTS-HD High Resolution Audio is selected as an optional surround sound format for Blu-ray Disc and HD DVD with constant bit rates up to respectively 6.0 Mbit/s and 3.0 Mbit/s. It is supposed to be an alternative for DTS-HD Master Audio where disc space may not allow it.
- : This is a function pack available on the computer platform only. It is found on soundcards with CMedia CMI8788/CMI8770 Soundcontroller.
- : This is a realtime DTS stream encoder. It is a part of ''.
- : A relatively new development. Intended for use in conjunction with a Dolby Headphone processor. It allows a virtual (as the name suggests) 5.1 surround sound to be heard through a standard pair of headphones. It provides a better spatial awareness than Dolby Headphone on its own.
